1. Field of the Invention
The present invention relates to a novel fluorine-containing mono- or poly-alkylene glycol and a method for producing the same, more particularly it relates to a novel fluorine-containing mono- or poly-alkylene glycol to be used and the starting material in producing a polymer having an excellent oxygene permeability, water swellability and contamination resistance, and a method for producing the same.
2. Description of the Related Art
A polymer constituting a contact lens must have oxygen permeability, and as the material for such a lens, a polymer obtained by polymerization of a monomer such as methyl methacrylate or a methacrylic acid ester type compound has been used in the prior art. Nevertheless, most of these polymers have an inferior oxygen permeability and a lens made of such a polymer can not be worn for a long time.
To improve the oxygen permeability of a methacrylic acid ester polymer, it has been proposed to make contact lenses of a silicone methacrylate type polymer having siloxane bonds introduced into methacrylic acid ester molecules (see, for example, Japanese Patent Publication (Kokoku) No. 52-33502), of an oxygen permeable polymer composed mainly of cellulose acetate butyrate, and of a fluorine-containing methacrylate type polymer (see, for example, Japanese Unexamined Patent Publications (Kokai) Nos. 57-51705 and 61-111308). Although these polymers have an improved oxygen permeability, compared with the methacrylic acid ester type polymers such as polymethyl methacrylate of the prior art, they are still not satisfactory, and polymers having a further improved oxygen permeability are required. Also, these polymers do not have a satisfactory contamination resistance, hydrophilic property, and water swellability.